The Center is focusing on the assessment of quality, utilization, and economics of primary care and how consumer, provider, management, and structural factors, as well as sources, methods, and levels of payment influence the results. Issues are sought out for which the evaluative process provides a basis initially for considering modification of some aspects of the delivery system, (e.g., use of mid- level manpower) and later for measuring the outcome or change. Definitive endpoints are being reached in studies concerned with (a) the utility of an encounter data information system in reviewing process and outcome of ambulatory care; (b) the use of information in medical decision-making in an outpatient encounter; (c) the feasibility of establishing peer review procedures for drug utilization and the effect of such a review procedure on utilization; (d) the health care behavior of populations who utilize different systems of health care; (e) the relationship of different mixes of manpower staffing to the quality, cost, and acceptability of services provided. Developmental activities are being carried out in 3 new areas related to the general objectives of the Center, i.e. emergency medical services, health education and manpower productivity. The settings for research are primarily the 4 delivery systems affiliated with the Johns Hopkins Medical Institutions, two of which are HMOs, one is a clinic in a housing project, and the 4th is an OPD which provides about one-half million services per year.